A mysterious new girl from Seito High that is presumed be Seito's "secret weapon". Easily a super A-rank, she wields one of the Hyakuhekitou swords with extreme efficiency. In the Ryuubi assassination attempt, she single-handedly defeated Kakouen Myosai, supposedly one of the more powerful A-ranks characters in the series, literally with her eyes closed while defending Ryuubi from henchmen. She presents herself with her eyes closed most of the time and is the only girl in Seito that does not wear the standard Seito High school girl uniform. She believes that violence is unnecessary and that blood-shed can be avoided to solve conflicts. She has deep respect for Kanu while their strengths rival one another.

Choun is arguably the most skilled fighter in both the manga and anime series so far (although she herself refers to Kanu as Seito's strongest fighter). Contrary to her looks, she is very laid back. Instead of being sent by Koumei to save Ryubi from Kakouen's assassination attempt, Choun was sent by Kanu to defeat Teni and Ryomou's dragon before claiming the Dragon Jade. There is no way to tell her true potential because of her limited fights and her lack of seriousness in them. So far, no fighter has given her a real challenge or even put a tear on her uniform. At the end of the series, she is seen doing a bad attempt at flower arranging. Though it is not clearly pointed out whether she harbors a dragon or not, it is seen in a few flashes, in between her fight scenes, that her eyes are cat-like when open, very similar to those who harbor their dragons with control. This anomaly is also seen in the last episode of the OVA when she plunges a warning sign at the eavesdroppers outside the hot springs. However, in transitions between scenes for Dragon Destiny, she has been drawn revealing a tiger tattoo on her left shoulder blade.